A new study links older fathers with higher risks for having children with psychiatric problems including bipolar disorder, autism and attention deficits.

JAMA Psychiatry, a journal of the American Medical Association, released the findings this week from American and Swedish researchers who examined data on more than two million Swedes born from 1973-2001.

Children fathered by men at age 45 and older faced risks for bipolar disorder almost 25 times greater than children whose dads were ages 20-24 at the time of their birth. The risk was 13 times greater for ADHD and more than three times greater for autism.

Older paternal age also more than doubled a child's likelihood for suicide attempts, schizophrenia and substance abuse.

The results add to evidence that DNA mutations can happen over time in men, but they do not prove that children of older dads are certain to have psychiatric problems. The risks for problems were greater, but still small. Less than one percent of kids of older dads had autism, ADHD or bipolar disorder.